From United States patent application US 2007/0049861 A1 a system is known for automated planning of an access path for a minimally invasive intervention of an area of the body. 3D image data of the body area is processed and bones and elements endangered by the intervention are segmented. The image data is displayed and the user marks a target position in the image. The system then automatically determines one or more access paths to the target position which do not run through bones and which do not intersect any elements endangered by the intervention. The one or more access paths are then presented to a user on a monitor and the user can interactively select and/or correct an access path. If no suitable path is found, the user is presented with alternatives in which injuries to the structures cannot be excluded. The endangered structures are highlighted to help the user with making an informed decision.
The known US patent application thus describes a planning system providing two kinds of information, i.e. safe surgical paths not intersecting with any important structure and unsafe paths intersecting at least one important structure. In addition to the unsafe path, the system indicates the structures harmed by the unsafe path. One of the disadvantages of the known system is that it can only be used for deciding, during planning of the surgery, which anatomical structure is going to be damaged. It does not provide a practical solution for a surgeon who wants to optimize the surgical path before as well as during surgery.